From 56cfe3f041a3dc65ccbe18ef0783ad73b19a207c Mon Sep 17 00:00:00 2001
From: aniakubik <ania.kubik@gmail.com>
Date: Tue, 29 Oct 2019 22:26:55 +0100
Subject: [PATCH] added euler totient function

---
 Math/eulerTotient.cpp | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)
 create mode 100644 Math/eulerTotient.cpp

diff --git a/Math/eulerTotient.cpp b/Math/eulerTotient.cpp
new file mode 100644
index 000000000..c71219641
--- /dev/null
+++ b/Math/eulerTotient.cpp
@@ -0,0 +1,37 @@
+#include<iostream>
+#include<cmath>
+using namespace std;
+
+/*
+this function calculate euler totien function
+*/
+
+long long eulerTotient(long long n){
+    
+    if(n == 1) return 1;
+    long long result = 1LL;
+    long long temp = n;
+    for(int i = 2; i <= floor(sqrt(n)) + 10; i++) {
+        if( temp % i == 0) {
+            int j = 0;
+            while(temp % i == 0){
+                j ++;
+                temp /= i;
+            }
+            result = result * pow(i,j-1) * (i-1);
+        }
+    }
+
+    if(temp == n){
+        return n-1;
+    }
+
+    return result;
+}
+
+int main(){
+    long long n;
+    cin >> n;
+    cout << eulerTotient(n);
+
+}
\ No newline at end of file